//
// Created by wze-zero on 2024/8/27 027.
//
#include <iostream>

using namespace std;

int main() {
    int t = 2, time = 0, num;
    cin >> num;
    time = num < 12 ? time + t : time + (num / 12) * 2 * t + t;
    cout << time << endl;
    return 0;
}